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Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for antibacterial activity of semiconducting photocatalytic materials

BS ISO 27447:2019This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.

© ISO 2019

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for antibacterial activity of semiconducting photocatalytic materialsCéramiques techniques — Méthode d'essai de l'activité antibactérienne des matériaux photocatalytiques semiconducteurs

INTERNATIONAL STANDARD

ISO27447

Second edition2019-07

Reference numberISO 27447:2019(E)

National foreword

This British Standard is the UK implementation of ISO 27447:2019. It supersedes BS ISO 27447:2009, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics.

A list of organizations represented on this committee can be obtained on request to its secretary.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

© The British Standards Institution 2019 Published by BSI Standards Limited 2019

ISBN 978 0 539 01075 6

ICS 81.060.30

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2019.

Amendments/corrigenda issued since publication

Date Text affected

BRITISH STANDARDBS ISO 27447:2019

This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.

© ISO 2019

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for antibacterial activity of semiconducting photocatalytic materialsCéramiques techniques — Méthode d'essai de l'activité antibactérienne des matériaux photocatalytiques semiconducteurs

INTERNATIONAL STANDARD

ISO27447

Second edition2019-07

Reference numberISO 27447:2019(E)

BS ISO 27447:2019

This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.

ISO 27447:2019(E)

ii © ISO 2019 – All rights reserved

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© ISO 2019All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.

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Published in Switzerland

BS ISO 27447:2019

This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.

ISO 27447:2019(E)

Foreword ..........................................................................................................................................................................................................................................vIntroduction ..............................................................................................................................................................................................................................vii1 Scope ................................................................................................................................................................................................................................. 12 Normative references ...................................................................................................................................................................................... 13 Termsanddefinitions ..................................................................................................................................................................................... 14 Symbols .......................................................................................................................................................................................................................... 25 Principle ........................................................................................................................................................................................................................ 36 Materials ....................................................................................................................................................................................................................... 4

6.1 Bacteria used and preparation for tests ............................................................................................................................ 46.1.1 Film cover method.......................................................................................................................................................... 46.1.2 Glass cover method ........................................................................................................................................................ 46.1.3 Bacteria preparation..................................................................................................................................................... 4

6.2 Chemicals and implements .......................................................................................................................................................... 56.2.1 General...................................................................................................................................................................................... 56.2.2 1/500 nutrient broth ................................................................................................................................................... 56.2.3 Nutrient broth .................................................................................................................................................................... 56.2.4 Nutrient agar ....................................................................................................................................................................... 56.2.5 Soybean-casein digest broth with lecithin and polysorbate 80 (SCDLP)........................ 56.2.6 Physiological saline solution ................................................................................................................................. 56.2.7 Physiological saline solution for washout .................................................................................................. 56.2.8 Non-ionic surfactant ..................................................................................................................................................... 6

7 Apparatus ..................................................................................................................................................................................................................... 67.1 Test equipment ....................................................................................................................................................................................... 67.2 Cover film ..................................................................................................................................................................................................... 67.3 Cover glass .................................................................................................................................................................................................. 67.4 Moisture preservation glass ........................................................................................................................................................ 77.5 Glass tube or glass rod ...................................................................................................................................................................... 77.6 Paper filter .................................................................................................................................................................................................. 77.7 Light source ............................................................................................................................................................................................... 77.8 UV radiometer ......................................................................................................................................................................................... 77.9 Punched metal sheet .......................................................................................................................................................................... 7

8 Test piece ...................................................................................................................................................................................................................... 98.1 Film cover method ............................................................................................................................................................................... 98.2 Glass cover method ............................................................................................................................................................................. 9

9 Procedure..................................................................................................................................................................................................................... 99.1 General ........................................................................................................................................................................................................... 99.2 Film cover method ............................................................................................................................................................................ 119.3 Glass cover method .......................................................................................................................................................................... 119.4 UV irradiation condition .............................................................................................................................................................. 129.5 Measurement of the number of living bacteria ........................................................................................................ 13

10 Calculation ...............................................................................................................................................................................................................1410.1 General ........................................................................................................................................................................................................ 1410.2 Film cover method ............................................................................................................................................................................ 1410.3 Glass cover method .......................................................................................................................................................................... 15

11 Test report ................................................................................................................................................................................................................16Annex A (informative) Examples of test results .....................................................................................................................................18Annex B (informative)Referencedataofcoverfilmsandcoverglasses ......................................................................20Annex C (informative) Reference data of damage caused by ultraviolet to bacteria ......................................22

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Contents Page

BS ISO 27447:2019

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ISO 27447:2019(E)

Bibliography .............................................................................................................................................................................................................................24

iv © ISO 2019 – All rights reserved

BS ISO 27447:2019

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ISO 27447:2019(E)

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 206, Fine ceramics. This second edition cancels and replaces the first edition (ISO 27447:2009), which has been technically revised. The main changes to the previous edition are as follows:

— updating of reference document and cross-references;

— replacement of “adhesive” with “cover” throughout;

— clarification of definition of “photocatalyst antibacterial activity value” (3.4, 3.5, 3.6, 3.7) in Clause 3;

— deletion of a definition of “fluorescent UV lamp” in Clause 3 due to updating of the reference document ISO 10677;

— inclusion of a statement in Clause 5 regarding treatment of results measured by the viable bacterial count method;

— NOTE 1 changed to body text in 6.1.3;

— revision of “storage period of 1/500 nutrient broth” from 1 month ago to 1 week ago in 6.2.2 (formerly 6.2.1);

— addition of a new subclause, 6.2.1, renumbering of subsequent subclauses and updating of cross-references in Clause 6;

— addition of a new subclause, 7.1, and renumbering of subsequent subclauses in Clause 7;

— revision of Figure 1, Figure 4 and Figure 5;

— addition of “paper filter” apparatus in 7.6;

— replacement of “black light fluorescent lamp” with “light source” in 7.7 (formerly 7.5) and revision of a statement in 7.7 that the light source shall be 351BLB or 351BL as specified in ISO 10677;

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BS ISO 27447:2019

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ISO 27447:2019(E)

— replacement of “ultraviolet light radiation mater” with “UV radiometer” in 7.8 (formerly 7.6) and inclusion of a statement in 7.8 that the UV radiometer shall be used as specified in ISO 10677;

— NOTE changed to body text in 8.1;

— addition of a new subclause, 9.1, and renumbering of subsequent subclauses in Clause 9;

— revision of storage time of “the bacteria suspension in case of not using immediately” from 4 h to 2 h in 9.2.1(formerly 9.1.1);

— NOTE 2 changed to body text in 9.2.2 (formerly 9.1.2);

— NOTE 2 and NOTE 3 changed to body text in 9.3.2 (formerly 9.2.2);

— addition of the test environment temperature (25 °C ± 3 °C) in 9.4.1;

— addition of a new subclause, 10.1, and renumbering of subsequent subclauses in Clause 10.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www .iso .org/members .html.

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BS ISO 27447:2019

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ISO 27447:2019(E)

Introduction

This document was developed for antibacterial activity as a result of continuing efforts to provide test methods for photocatalytic materials. However, antibacterial activity cannot be measured for test pieces with permeable or rough surfaces, so other test methods are required.

Under the irradiation of photons, photocatalysts show diverse functions, such as the decomposition of air and water contaminants, as well as deodorization, self-cleaning, antifogging and antibacterial actions. These functions of photocatalysts are generally based on the action of active oxygen species such as hydroxyl (OH) radicals formed on the surface of a photocatalyst (References [14] and [15]). The energy- and labour-saving nature of photocatalysis has attracted keen interest when the photocatalyst is activated by sunlight (or artificial lighting).

Practical applications of photocatalysts for both indoor and outdoor use have rapidly expanded in recent years. Many kinds of photocatalytic materials have been proposed or are already commercialized, based on ceramics, glass, concrete, plastics or paper. Such materials are produced by either the coating or mixing of a photocatalyst; in most cases, titanium dioxide (TiO2).

However, the effect of photocatalysis is not easily inspected visually, and no appropriate or official evaluation methods have been available to date. Some confusion has thus arisen as photocatalytic materials have been introduced. Furthermore, the above-mentioned diverse functions of photocatalysts cannot be evaluated with a single method; thus, it is necessary to provide different evaluation methods for air purification, water decontamination and self-cleaning.

This document applies to the testing of the antibacterial activity of photocatalytic ceramics and other materials produced by either the coating or the mixing of a photocatalyst. Standards for testing the antifungal activity that use photocatalytic materials will be developed separately.

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BS ISO 27447:2019

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BS ISO 27447:2019

This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for antibacterial activity of semiconducting photocatalytic materialsWARNING — Handling and manipulation of microorganisms that are potentially hazardous requires a high degree of technical competence. Only personnel trained in microbiological techniques should carry out tests.

1 Scope

This document specifies a test method for the determination of the antibacterial activity of materials that contain a photocatalyst or have photocatalytic films on the surface, by measuring the enumeration of bacteria under irradiation of ultraviolet light.

This document is intended for use with different kinds of semiconducting photocatalytic materials used in construction materials in flat sheet, board, plate shape or textiles that are the basic forms of materials for various applications. It does not include powder, granular or porous photocatalytic materials.

This test method is usually applicable to photocatalytic materials produced for antibacterial effect. Other types of performance of photocatalytic materials, i.e. antifungal activity, antiviral activity, decomposition of water contaminants, self-cleaning, antifogging and air purification, are not determined by this method.

The values expressed in this document are in accordance with the International System of Units (SI).

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 10677, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ultraviolet light source for testing semiconducting photocatalytic materials

ISO 80000-1, Quantities and units — Part 1: General

3 Termsanddefinitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp

— IEC Electropedia: available at http: //www .electropedia .org/

3.1photocatalystsubstance that carries out many functions based on oxidization and reduction reactions under ultraviolet (UV) irradiation, including decomposition and removal of air and water contaminants, deodorization, and antibacterial, antifungal, antiviral, self-cleaning and antifogging actions

INTERNATIONAL STANDARD ISO 27447:2019(E)

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BS ISO 27447:2019

This is a preview of "BS ISO 27447:2019". Click here to purchase the full version from the ANSI store.